Seating products or the like which employ sinuous springs are known. Usually the seating product is divided into a back section which supports the back of a person sitting on the product and a seat section upon which the user sits. Either section may comprise a generally rectangular wooden frame made up of four orthogonal rails, typically made of wood, and a plurality of sinuous springs extending between a pair of opposed rails of the frame. In order to secure the sinuous springs to the opposed rails of the frame, generally clips are secured to the top surfaces of the opposed rails at spaced intervals in order to space the parallel sinuous springs. The endmost segments or portions of the sinuous springs are inserted into the clips in order to secure the sinuous springs to the opposed rails of the frame. Due to the inherent stiffness of the sinuous springs, the sinuous springs are commonly arched or domed so as to provide a softer, more comfortable "feel" for the user. Even with arched or arcuate sinuous springs, if the sinuous springs are secured directly to the frame by metal clips or other conventional securements, the seating product generally has a relatively "hard," less-than-desirable seating surface because of the firmness of the sinuous springs.
In order to increase the softness or give of either the back or seat section of a seating product employing sinuous springs, several different types of connectors connecting the endmost segments of the sinuous springs to the frame have been employed. U.S. Pat. No. 4,157,173 discloses rail connectors in the form of torsion springs connecting the endmost segments of the sinuous springs to clips secured to the rails of the seating product. Similarly, U.S. Pat. Nos. 3,210,064 and 3,311,366 disclose coiled springs extending between and secured to the endmost segments of the sinuous springs and the clips secured to the frame in order to increase the resiliency of the sinuous springs. When any of these types of connectors are used to secure the endmost segments of the sinuous springs to the frame, the endmost segments of the sinuous springs may be moved inwardly from the opposed rails of the frame, thus increasing the resiliency or softness of product.
The use of clips to secure the sinuous springs or connecting elements to the frame often requires that the frame be made of a relatively hard wood product such as oak or maple, because the clips must be nailed or stapled in place securely in order to support the load placed on the sinuous springs. Such hardwood frames present a drawback to the manufacture of sinuous wire seating products because of the expense of the hardwood material from which the frame must be made.
An additional drawback to using clips to secure the endmost segments of the sinuous springs to the frame is that often the interaction between the endmost segments of the sinuous springs and the clips creates unwanted noise due to the movement of the endmost segments of the sinuous springs inside the clips secured to the frame.
Another type of seating or furniture product uses a plurality of webbing strips rather than sinuous springs extending between opposed rails of the frame in order provide the supporting surface of the product. Such a construction is most commonly used on outdoor seating furniture. This type of construction does not provide a comfortable seating or back surface for the user, primarily because the webbing lacks sufficient resiliency or give once a load is placed on the webbing.
Regardless of whether a seating product employs arched sinuous springs or lengths of webbing to make the body of the product, the resiliency of the product is generally uniform or symmetrical. Oftentimes, it is desirable to increase the firmness of a particular portion of a seating product. For example, in the back section of a seating product, an increased firmness in the lower portion of the back section may be desirable in order to provide lumbar or lower back support.
Therefore, it has been one objective of the present invention to provide a seating product which does not employ clips in order to secure the endmost segments of arched sinuous wire springs to the frame of the seating product.
It has further been an objective of the present invention to provide a seating product which does not require the use of hardwoods for the frame of the seating product.
It has been a further objective of the present invention to provide a seating product in which sinuous wire springs may be secured to lengths of webbing in different locations in order to provide lower back or lumbar support for the user of the seating product.